A current flowing through a conductor is said to be one ampere if 1 coulomb of charge flows through the conductor in 1 second. This note provides us an information on direct current.
The resistance of a conductor is defined as its ability to oppose the flow of charge through it. It is measured by the ratio of the potential difference V across its ends to the current I flowing through it. This note provides us an information on electrical resistance.
Resistances are said to be connected in series when they are joined end-to-end, so that same current flows through each of them. This note provides us an information on a combination of resistance and galvanometer.
A galvanometer can be converted into ammeter by connecting a low resistance called shunt in parallel to the galvanometer. This note provides us an information on conversion of a galvanometer into ammeter and voltmeter.